Building things by yourself, especially with leftover material, has this air of post-peak self-reliance. But, often, that supposes the existence of industrially made products. When you need wood, for instance, you can get planks or beams from a store or, more in a post-peak style, you use material taken from discarded furniture. But in both cases, the wood you use has been industrially processed.
Suppose, instead, that you live in a remote village in the mountains, a place like Valboncione, in Italy. Up to not so long ago, clearly, they didn't have access to industrially processed wood. Still, they needed to build shacks and they managed to do that with what they had. The results are remarkable, in a sense, although not exactly the kind of place where you can find shelter from a gust of cold wind!
There are several of these shacks in the village; all built in the same way and none can be older than a few decades - they couldn't possibly have lasted more than that. They way they were made is amazing: look at how all sorts of beams and planks have been joined together. It looks like all the elements in wood were made by hand, one by one.
And look at how the hinges for one of the doors were made:
If this is not post-peak, what is?